1. Field of the Invention
The present invention generally relates to a method and system for managing a Push-To-Talk (PTT) over Cellular (PoC) box in a PoC system, and more particularly to a method and system for providing desired media when a PoC User Equipment (UE) retrieves media information stored in a PoC box and requests a desired media transmission in a PoC system.
2. Description of the Related Art
With the significant development of mobile communication and the extension of a communication network, variously extended services and applications using mobile phones are being provided. According to various user requests, service is being extended to a positioning service, multimedia service, Push-To-Talk (PTT) service, and so on beyond a simple call service. Specifically, the PTT service supports various additional functions, such as an instant messenger function, state display function, etc., as well as a group call and a voice call that are possible in a conventional radio system or a Trunked Radio System (TRS).
A concept of this PTT service is being actively discussed to standardize a PTT over Cellular (PoC) service using a mobile communication network. One of characteristics of the PoC service different from a conventional mobile communication service is that users can perform communication while moving between multiple sessions according to need. The requirement that users should be able to perform communication while moving between multiple sessions is prescribed in the PoC 1.0 standard of the Open Mobile Alliance (OMA) serving as an organization for developing a standard for a mobile communication service.
As defined in the PoC 1.0 standard, media data is sent only to PoC clients participating in a PoC session in real time. Because of this characteristic, users who do not participate in the PoC session for various reasons including, for example, battery discharge, absence, etc., cannot receive a media stream, such as voice or the like, in a one-to-one (1-1) or group PoC session. That is, the PoC 1.0 technology does not support a function of a voice mail box supported in a conventional communication.
To address a problem when a PoC User Equipment (UE) does not participate in a session and cannot receive a media stream, OMA PoC Release 2 considers a PoC box whose function is similar to that of a Multi Media (MM) box for a conventional Multi Media Service (MMS). A PoC box service is a service in which a PoC client incapable of participating in a 1-1 or group PoC session in real time participates in an associated PoC session using a particular physical or logical storage system. As described above, the PoC box stores media sent in a session when a PoC client participates in an associated PoC session. Subsequently, the stored media are sent and reproduced according to the PoC client's request.
When the PoC client participates in a PoC session and makes a request for receiving stored media from a PoC box storing media sent in the session, all stored media are provided from the PoC box to the PoC client. A user of the PoC UE receives undesired media, and also the right to select media desired by the user is limited.